EAS100 Lecture Notes - Lecture 9: Paleozoic, Exoskeleton, Supercontinent

• School: University of Alberta
• Department: Earth and Atmospheric Sciences
• Course: EAS100
• Professor: Korhan

Document Summary

Geologists have assembled a geologic column that summarizes in chronological order the succession of known rock units. Hadean, archean, proterozoic, paleozoic, mesozoic and cenozoic eons. Correlation gives relative timing of strata used to develop a geological time scale. Isotopic (absolute) ages can be related to fossil (relative) ages allows calibration and extension of the timescale. Before 3. 8 ga including earliest known rocks . Heating from collisions and radioactive decay melted most of early earth. Heavy material settled to the centre to form the metal core and outer parts cooled/solidified. Intense meteorite bombardment left craters, preserved on planets that have no active. Interior of earth was hotter than now (more radioactive isotopes) First evidence of life around 3. 5 ga. Starts with first animal shell fossils ~ 542 ma. Land colonized by plants around 400 ma. Followed by first land animals (insects, amphibians) In late paleozoic time, continents became amalgamated into a single supercontinent pangea.